The present invention relates to an air introduction system, and more particularly to an active noise control speaker mounting arrangement.
Manufacturers have employed active and passive methods to reduce engine noise within the passenger compartment. Such noise frequently emanates from the engine, travels through the air induction system and emanates out of an inlet of the air intake into the passenger compartment.
Active systems use a speaker to create a canceling sound that attenuates engine noise. The sound created is out of phase with the engine noise and combines with this noise to result in its reduction. Generally, this sound is generated in proximity to the inlet of the air induction system. In one such system, a control unit, such as a digital signal processor, obtains data from the vehicle engine, creates a predictive model of engine noise, and thereby generates the appropriate cancellation signal based on the results of this model. This signal is then transmitted to the speaker, which transforms this signal into a canceling sound. Because the control unit may not perfectly model engine noise, an error microphone is placed in proximity to the intake of the air induction system to determine if engine noise need be further attenuated.
Typically, the error microphone is placed near the air inlet. The speaker of the system is generally attached to the air induction system. Conventional speaker arrangements utilize a speaker support ring having a multiple of lobes. The lobes receive fasteners for attachment of the speaker to the speaker support ring. The multiple lobes result in a relatively large support ring housing which increases the speaker mounting face area. Furthermore, a large number of lobes are required to assure a proper seal of the speaker of its chamber to prevent damage caused by weathering including snow, mud, ice, stones, leaves insects, and other environmental conditions.
Accordingly, it is desirable to provide a mounting arrangement without utilizing conventional fasteners for an active noise control speaker which hardens the speaker against environmental conditions while increasing the effective speaker face area.
The air introduction system according to the present invention provides an active noise control system which includes a speaker assembly. A speaker is supported by a speaker support ring which is mounted to a speaker housing. A speaker protection cone mounts to the speaker housing to further protect the speaker within the speaker housing.
In one speaker assembly, the speaker housing includes a plurality of extensions which extend radially from an outer periphery of the speaker housing. The speaker support ring includes an edge which at least partially surround the extensions. That is, a lip of the edge is substantially perpendicular to xe2x80x9csnapxe2x80x9d around the extensions. The speaker protection cone is attached directly to the speaker support ring.
In another speaker assembly, the speaker support ring includes a plurality of apertures through a flange which closely fits a speaker housing. This speaker assembly is assembled through heat application. The housing edge and the speaker protection cone edge are heated to a melting point of the material and the speaker support ring is sandwiched therebetween. Heated material from the housing edge and the speaker protection cone edge pass through the apertures to provide an effective bond therebetween.
Another speaker assembly according to the present invention includes a speaker support ring having a plurality of teeth along the outer periphery. The teeth face inward toward the center of the speaker support ring such that when the speaker support ring is mounted to the speaker housing the teeth engage the outer periphery thereof. A separate process may then attach the speaker protection cone to the housing.
The present invention therefore provides a mounting arrangement without utilizing conventional fasteners for an active noise control speaker which hardens the speaker against environmental conditions while increasing the effective speaker face area.